Thermostatic filot control system for burners



July 26, 1927. 0' FOX ET AL THERMOSTATIC PILOT CONTROL SYSTEM FORBURNERS 26 1 I July v 0. FOX ET AL THERMOSTATIC PILOT CONTROL SYSTEM FORBURNERS Filed April 14. 1926 zshqets-shet 2 I I I r 1 r I 1 i I I, 1 1

. son, be extin uished.

Patented July 26, 1927.

- UNITED. STATES PA ENT oFFIcE.

OTTO FOX, 01' CLEVELAND, AND WILLIE. I. STARK, OF EAST CLEVELAND, CHIC,AS- SIGNOBS 1'0 THE BRYANT HEATER AND MANUFACTURING COMPANY; OF CLEVE-LAND, 0310,; coarona'rxon or 0310.

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Application fled April 14', 1820. Serial No. 101,888.

This invention relates to a thermostatic pilot control for gas burnersand has for its object to provide an improved and highly efficientsystem for preventing the flow of gas to the main and pilot burners inthe event that the flame at any one or more of the pilot burners becomesextinguished.

In accordance with our invention and in its preferred embodiment, a maincontrol- 1 ply of as into the portion of the chamber valve is employedpreferably a diaphragm valve which is actuated automatica ly through themedium of a thermostat or other control device such as a steam regulatorto control the flow of as to the main burner "or burners and inacfdition, we provide an auxiliary valve which is preferably also adiaphragm valve and which is actuated throu h the medium of a pilotthermostat and o --a valve associated therewith for controlling the mainvalve insuch a way as to prevent the latter bein opened if the flame atthe pilot burner shou d, for any rea- The invention may be furtherbriefly summarized asconsisting in certain novel details of constructionand combinations and arrangements of parts which will be described inthe specification and set forth in the appended claims.

In the accompanying sheets of drawings Fig. 1 is a more or lessconventional representation of a system embodying my invention, partsbeing in elevation and parts beingin section;

Fig. 2 is an enlarged view part1 -.in elevation and partly in section ofthe pilot burner and control mechanism associated directly therewith;and

Fig. 3 is a sectional view through themain diaphragm valve showing theadaptation for a main control somewhat different than that illustratedin Fig. 1.

Referring now to the drawin' s,"10 represents the main gas supply piperom which gas is supplied through an automatically controlled valve 11,on the outlet side of which is a pipe112 connected to a. manifold 13 towhich any number of maingas burners 14 may be connected, each separatelycontrollable through the usual hand operated valve 15. [The main valve.11 is pref erablv a diaphragm valve and comprises a chamber 11 and adiaphragm 11" wh'c'h is above tlediaphragm, the latter will drop ontothe seat and prevent the flow of gas to the main burners until the"pressures are again unbalanced by reducing the pressure a ove thediaphragm.

I In thenormal operation of the system the flow of gas to the upper artof the chamber is controlled automatical y by a valve actuated in any ofthe usual ways as by a thermostat or steam pressure regulator. When athermostat. is used it may be of the type which controls the t nperatureof the water i in the storage tank r it may control it indirectly aswhen utilized in the control of room temperature in which event thevalve ma be actuated by a motor in turn con; tro led by the thermostat.

In Fig. 1 we have shown a thermostat 16 of the first named t pe adaptedto actuate a valve 17 which, w ien opened permits gas to flow to theupper part of the chamber 11 so as to seat tie diaphragm 11". In thisinstance a gas supply pipe 18 is connected to the lower part of the maincontrol valve 11 and this is connected by a pipe 19 to the intake sideof the chamber 17' of the thermostat controlled valve 17. The outletside of this chamber has connected to it a pipe 20 in turn connected toa pipe 21 communicating with the upper part of the chamber 11 of themain control valve 11. It will be seen that when the thermostat 16 opensor permits valve 17 to open gas will flow from the lower side chamber ofthe main control valve 11 through pipes 18, 19,

through valve '17 and p1pes'20 and 21 to the upper side of the chamberof the main control valve thus uahzing the pressures on opposite sidesof t e diap lragm and per- .mittmgitto drop by gravity onto the seat Iis then reduced through the medium of an gas which is admitted totheupper partof i escapement burner 22 having a small orifice 23 andconnected by pipe 24 to pipe 21 leading to the upper part of the chamberof the main control valve. In consequence on the closing of thethermostat controlled valve 17, the pressure above the diaphragm isreduced and the diaphragm is liftedv permitting gas again to flow to themain burner or burners 14.

In Fig. 3 a main control valve 25 is shown having a chamber 25 and adiaphragm 25 which is operated similarly to that shown in Fig. 1 but.the flow of gas to the upper part of the chamber 25 is controlled in asomewhat different manner. In this instance, the

chamber 25 to seat the iaphragm, is supplied through a passageway 25formed in the valve ohamber25, the lower end of this passagewayconnecting with the intake side of the'valve 25. The upper end ofv thispassageway isadapted to be placed in communication with the upper partof the valve chambcr 25- by a small valve 26 arranged in the upperpart'of the chamber. The opening opened by the lowering of the weightedlever and is closed by a small springwhen the weighted lever is.elevated but the valve 26 can be constructed and operated otherwise ifdesired.

.In Fig. 3 the upper part of the valve chamber 25 has connected to itthe pipe 21 lead-' ing to the escapement burner 22, asshown in Fig. 1,and the lower part of the chamber 25 has connected to it a gas supplypipe 18 as in the construction first described.

Coming now to the parts or features more directly involving myinvention, the pilot burner which is associated with the main burner inFig. 1 is shown at 28. As there may be any number of main burners 14 sothere may also be any number of pilot burners 28, one associated witheach main burner if desired. By reference particularly to Fig. 2 it willbe seen that the pilot burner is provided at the top with a series oforifices 29 and is provided at the bottom with a restricted orifice 30.Gas is normally supplied to the pilot burner by a pipe 31 connected to achamber 32. This in turn is connected by a pipe 33 to a'pilot burnermanifold 34 to which the different pilots are connected if more than onepilot is employed. By referring again to Fig. 2 it will be noted thatassociated with each pilot 28 is a thermostat .35 which in this instanceis attached directly to the pilot a short. distance below the burneropenings 29.. The lower end of the thermostat abuts againstn rod 36which extends freely through a pipe 37 connected to the chamber 32. Therod 36 also extends into the chamber 32 and at its inner end is providedwith a valve 38 adapted to engage a seat 39 which is formed in chamber32 and toward which the valve is urged by spring 40. The arrangement issuch that the thermostat 35 when heated 'will allowthe valve 38 to beseated so as to close off communication between chamber 32 and pipe 37,but when the thQI'IIIOSltli. is cooled it unscats the valve against thepres.- sure of spring 40 and allows gas to flow from the chamber 32through pipe 37 as well as through the pipe 31 leading to thepilotburner.

At the outer end of the pipe 37 there is a gas outlet pipe '41 having'a,seaies of orifices 42, the area of which is greater than that of theorifice 30 leading to the pilot burner and in fact greater than theaggregate area of the orifices 30 of all the pilot burners assuming thatthere may be more than one. The function of the thermostat and of thearrangement illustrated inFigs. 1 and 2 in conplained presently.

Gas is adapted to be supplied to the pilot manifold 34 and thereby tothe different pilot burners from the pipe 18 which, as previouslyexplained, is connected to the. lower side of the chamber of the maincontrol valve 11 shown in Fig.1 or main con.- trol valve 25 of Fig. 3.The pipe 18 leading to the lower side of the chamber of the main ofconnection for the supply pipe for the pi'lot'burners but a connectionwith any other point 011 the intakeside of the main control valve or onthe intake side of the diaphragm 11 thereof will do as well.

It is an important feature of my invention nection with the pilot burnerwill be excontrol valve is simply a convenient point that thereisarranged between the-pilot manifold 34 and the pipe 18 a specialautomatic valve 43 which is preferably a. diaphragm valve composed of acasing or chamber 43 and a diaphragm 43 having an upper seat 43 and alower seat 43 7 Two pipe connections are made with chamber 43" on eachside of the diaphragm 43 The connections on the upper side consist of apipe 44 connected to a. pipe 45 in turn connected to supply pipe 18communicating with the lower side of the chamber of the main controlvalve, as already explained, the other connection to the upper side ofthe chamber being a pipe 46 leading to the pilot manifold 34. It may behere stated that normally the diaphragm is down or in engagement withthe lower seat 43, in whichevent' gas passes' normally closed.

nose-17c continually from pipe 18 and pipes 45, 44'

the upper part of the chamber 43' and pipe 46 to t e pilot manifold 34.

The two ipe connections with the lower to a pipe 49 which in turn isconnected to pipe 21 leading to the up r side of the chamber of the maincontro valve.

The apparatus is completed b two small by-pass plpes one consisting oby-pass 50 between the gas supply pipe leading to the upper part of thechamber 43 and the g therefrom. This provi ed with a cock 51 smallpush-button which is preferab y cock. The other by-pass ipe 52 isbetween pipe 49 and pipe 46, this y-pass pipe being provided with anordinary cook 53. There is preferably provided also a cock 11,54. in gassupply pipe 45 between pi 44 shown in Fig. 1. The 000 51 and 53 are Thesystem operates as follows:

During normal operation gas flows continuously from the lower part ofthe maincontrol valve'and through'the upper partof the auxiliarydiaphragm valve to the pilot burner or burners 28. During this normaloperation the auxiliary valve controlled by thermostat 35 is closedsince the thermostat is heated by the flame at the pilot burner.

Y In consequence no gas passes through the pipe or tube 37. During suchnormal operation the flow of gas to the main burner or burners iscontrolled in the customary way by the thermostat or steam regulator,the

latter controlling the valve which permits or stops flow of gas abovethe diaphra m of the main control valve so as to perm1t the diaphragm tobe seated or unseated'. If While the gas is shut oil from the mainburner or burners, the flame .at the pilot burner 28 or any one of theseries of pilot burners should be extinguished the thermostat 35associated withthe particular pilot burner in question cools ofi and asit cools it unseats or opens valve.38 permitting a free flow of gasthrough pipe 37 and orifices 42. As before stated, these ports are soproportioned that they are much larger than the combined area of theorifices of all the pilot burners connected to manifold 34. The openingof valve 38, therefore,results in an increased amount of gas immediatelypass ing through the'entire pilot line and produces a decided drop inpressure in the upper part of the chamber of the auxiliary-diaphragmvalve 43. Since the pressure above diaphragm 43 is reduced it becomesoverbalanced by the pressure below the diaphragm and causes the diaphrato raise and to be seated on the upper va ve seat 43. lhe raising of thediaphragm shuts off nd 47, as

the flow of gas to all pilot burners and additionally it permits gasto'flow through pipe 47 and throu h the lower part of the chamber of thevsfive 43 and h pi cs 48, 49 and 21 to\ the upper part of t e c iamberof the main control valve.

Now if the supply of gas through pipes 19 and-20 to pipe 21 is cut oilby the action of the steam regulator or thermostat the diaphragm of themain valve is unable to rise as the pressure above it is maintained bythe flow of gas through the auxiliary diaphragm valve and pipes 48 and49. Thus the flow of gas to the main burners and to the pilot burners isshut ofl and during this time the flow of gas through escapement burneris restricted to the very small amount that will pass through theorifice 23, this being practically a negligible amount.

Let it be assumed that the house owner desires to relight the burners14. Push button 51 which is provided to permitrelighting with safety isdepressed and gas flows throu h the small line to pilot manifold 34 andto the pilot burner or burners. The gas may now be lighted at the ports42.

Durin this time the diaphragm 43 of the aux' iary diaphragm valve willremain seated against the upper valve seat 43 since the ports 14 are solarge in comparison with that sufficient gas pressure would be unable tobuild up, in the upper part of the chamber of'the auxiliary diaphragmvalve to cause the diaphragm to dro onto the seat 43.

However, as soon as t e thermostat 35 be the passage through push-buttonvalve 51 pipe 50 and pipe 46 to cause the diaphragm 43 to be lowered onthe seat 43 this being true because the flow of gas is restricted by theorifice or orifices 30 of the pilot burner bodies.

The flow of gas through pipes 49, 48 and 21 to the upper part of thechamber of the main valve 11 is now-stopped permitting the gas pressurein the upper chainber of valve 15 to be relieved through escapementburner 22. Diaphragm 11 is now raised by gas pressure beneath permittinggas to flow to burner or burners 14.

Push button valve 51 is normally held shut by a spring, and as soon asthe diaphragm 43 of the auxiliary diaphragm valve has dropped onto seat43 the push button may be released and the pilot or pilots will be fedin the normal manner through pipes 45,

generally operated by one hand and the no pilot or pilots are lit withthe other, it is person to operate the push button valve and light allthe pilot burners. Accordingly bypass 52 and cook 53 with .its' smallorifice are provided to facilitate the lighting of such boilers. t

In the latter case the operator'will open cock 53 instead of the pushbutton cock 51 thus permitting a small amount of gas to flow throughcock 53 to pilot manifold 34 and pilots including the orifices 42, thisgas ofcoursc being fed through pipe 45 leading from the lower part ofthe chamber of the auxiliary diaphragm valve 4;). The pilots may now belighted and push button cock 51 may be opened to increase the flow ofgas and hence the heat of the pilots. As soon as the pilots are heatedand the valves 38 close thus restricting the flow of gas through thepilots, pressure accumulates in the upper part of the chamber ofauxiliary diaphragm valve 43' causing the diaphragm 43" to be seated onthe lower seat 43 thus stoppin the flow of gas through the lower part ofthe chamber of auxiliary diaphragm valve but there is a sufiicient flowof gas through by-pass pipe 52 into pipe 49 to prevent the lifting ofthe diaphragm of the main shut-off valve until cock 53 is closed andwhen this cock is closed the system will operate normally. I

The lower end of pipe 44 which normally supplies gas to the upper partof the chamber of the auxiliary control valve 43 is prefprovided with anorifice 44, this erably orifice ein'g comparatively large. When thepilot is burning in the normal manner the flow of gas is so small thatthis orifice" has no throttling effect but when the flame isextinguished the increased flow of gasthrough the orifice causes it toreduce the pressure on top of the diaphragm 43 much more rapidly thanwould be the case if the full area of piping 44 were available for theflow of gas. The apparatus will function without this orifice but not asquickly as desiied, the principal effect of the orifice being thereforeto accelerate the action of the pilot. I I

Having thus described our invention what we claim is: a 1. In athermostatic pilot control system for burners, a main burner, a pipe forsupplying gas thereto, a pilot burner having a thermostat, a' .valveassociated with the thermostat and adapted to be opened when thethermostat cools by the extinguishment of the flame of the pilot burner,a main control valve, and means whereby the. opening of the firstmentioned valve prevents opening of the main control valve.

' 2. In a thermostatic pilot control system for burners, a main burner,a pilot bdrner,

oam-77o a main control valve, a-thermostat associated" with the pilotburner,.a valve adapted to be operated.- thereby and a third valvecontrolled by the second mentioned valve and servin to prevent theopening of the main contro valve when the flame is extinguished.

at the pilot burner.

In a thermostatic pilot controlsystem for gas burners, a main burner, apilot bumer. an 11111201118110 main control valve of the pressureactuated type, a thermostat associated with the pilot burner, a valvecontrolled thereby, a third valve which is controlled by thesecondmentioned valve and serving to cause pressure to be applied to the mainvalve so as to preventthe opening thereof when the flame is extinguishedat the pilot burner.

4. ln a thermostaticpilot control system for burners, a main burner, apilotburner, a gas supply pipe, ajmain'control valve for controlling thesupply of gas to the main burner, means comprisingadiaphragm valve forcontrolling the supply of-gas to the pilot burner and for preventing theopening of the main control valveiand means operated by the thermostatforcontrolling said diaphragm valve. a

5. In a thermostatic pilot control system for burners, a main burner, apilot burner having a thermostat. associated therewith, a

main control valve of the diaphragm type for controlling the flow of gasto the mamv burner, means comprising an auxiliary control valve of thediaphragm type for controlling the flow of gas to the pilot burner andfor controlling the flow 'of gas to the main control valve to preventthe opening thereof and means operated by the thermostat for controllingsaid auxiliary control valve.

6. In a thermostatic pilot control system for burners,-a main burner, apilot burner having a .thermostat, a main control valve of the diaphragmtype for controlling the flow of gas to the main burner, meanscomprising an auxiliary control valve of the diaphragm type forcontrolling the flow of gas to the pilot burner and the fiow of gas toone side of the diaphragm of the main control valve, and meanscomprising a valve operated by the thermostat for controlling theauxiliary control valve.

7. In a thermostatic pilot control system for burners, a main burner, apilot burner having a thermostat associated therewith, a; gas supplypipe, a main control valve of the diaphragm type for controlling theflow of and ada ted to-be opened through the movement 0 the thermostatwhen the flame at the pilot burner is extinguished for controlling theauxiliary control valve.

8. In a thermostatic pilot control system for burners, a main burner, apilot burner having a thermostat, a gas supply pipe, at main'controlvalve of the diaphragm type for controlling the flow of gas to the mainburner, means comprising an auxiliary control valve of the diaphragm=ty. for controlling the flow of gas to the pilot burner, a normallyclosed valve associated with the thermostat and adapted to be openedthrou h the movement of the thermostat when he flame at the pilot burneris extinguished, and means by which a drop in gas pressure produced bythe opening of the thermostatically controlled valve operates to controlthe auxiliary control valve.

9. In a thermostatic pilot control system for burners, a main burner, apilot burner having a thermostat associated therewith, a

gas supply pipe, a-main control valve of the diaphragm type forcontrolling the flow of gas to the mam burner, and means comprising a.normally closed valve associated with the thermostat and adapted to beopened through the movement of the thermostat when the flame of thepilot burner is extinguished for controlling the main control valve.

10. In a thermostatic pilot control system burner, means comprisin anormally closed l valve associated with t e "thermostat and K,

adapted to be opened throu h the movement of the thermostat when t eflame at the pilot burner is extinguished, and means whereby thereduetion in gas pressurecaused by the opening of said normally closedvalve effects the closing of the main control valve. 11. A pilot controlvalve of the type described comprising a pilot burner, and a thermostatassociated with the pilot burner, adapted to open a normally closedvalve upon the extingnishment of the pilot flame to reduce the pressurein a gas supply line.

12. A pilot contrbl valve of the type described comprising a member adated to be secured to a gas supply pipe, 9. pi ot burner carried by saidmember, a thermostat associated with said pilot burner, and 8. normallyclosed valve mounted in said member, the extinguishment of the flame ofthe pilot burner causing the opening of said valve tov thereby reducethe pressure within the gas supply p1 In test niiony whereof, wehereunto afiix our signatures. i

OTTO FOX. WILLET E. STARK.

